There are many devices for teaching of guitar, mandolin, ukulele or other stringed instruments. One such prior art device is U.S. Pat. No. 2,145,718, issued to A. G. Finney, Jan. 31, 1939, for STRINGED MUSICAL INSTRUMENT, wherein a movable slide is positioned on runners which along with a provided punch card is used to produce particular chords in particular keys of music. Another prior art patent representative of the field, is U.S. Pat. No. 3,218,904, issued to L. M. Hartman, Nov. 23, 1965, for GUITAR TRAINING DEVICE. This patent discloses a training device which is adapted to fit under the strings of a guitar neck and which contains identification for particular chords. Still another prior art device is disclosed in U.S. Pat. No. 3,494,240, issued Feb. 10, 1970, to A. G. Laselva et al., for SOUNDING BOX, in which a hollow box is provided with a single bridge and strings of different diameters to illustrate the physics involved in the production of tones.
All of these devices are adequate for their intended purposes, but none is particularly adapted to provide a teaching device for serious students of string instruments which allows the students to practice left-hand fingering and also right-hand strumming or plucking.